Crank-case ventilation filter set equipped with check valve

ABSTRACT

A crank-case ventilation filter set. A crankcase ventilation filter filters oil from blow-by gas. An inlet pipe transports the blow-by gas from an engine to the filter. An outlet pipe transports the blow-by gas from the filter to an intake device. An oil return pipe transports oil, such as by gravity, from the filter to an oil pan provided at a lower portion of the engine. A valve for preventing back-flow of oil is provided in the oil return pipe. The valve is disposed in the oil pan above an oil top limit line of the oil pan.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to, and the benefit of, Korean Patent Application No. 10-2007-0118031, filed in the Korean intellectual Property Office on Nov. 19, 2007, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a crank-case ventilation filter.

(b) Description of the Related Art

Blow-by gas generated in a vehicle engine returns to an intake device of the engine, so a filter device is provided to filter out engine oil particles in the blow-by gas. The oil accumulated in the filter returns to the oil pan through a return pipe.

However, when pressure inside the oil pan rises, gases inside the oil pan can flow backward through the return pipe. The oil from the filter can also flow backward to an inlet duct.

To prevent the backward flow of gases, the return pipe is submerged in the oil in the pan, and a check valve is provided in the filter. However, if the cheek valve malfunctions, the oil accumulated in the filter flows backward through the inlet duct.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

SUMMARY OF THE INVENTION

A crank-case ventilation filter set is disclosed. A crankcase ventilation filter filters oil from blow-by gas. An inlet pipe transports the blow-by gas from an engine to the filter. An outlet pipe transports the blow-by gas from the filter to an intake device. An oil return pipe transports oil, such as by gravity, from the filter to an oil pan provided at a lower portion of the engine. A valve for preventing back-flow of oil is provided in the oil return pipe. The valve is disposed in the oil pan above an oil top limit line of the oil pan.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of a crank-case ventilation filter set according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of a check valve according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

Referring to FIG. 1, an engine 100 has therein an outlet pipe 104 for outputting blow-by gas. A filter 106 is connected to the outlet pipe 104, and an inlet pipe 102 is connected to the filter 106 to return blow-by gas to an intake device (not shown) of the engine 100.

A return pipe 110 is connected near the bottom of the filter 106, and to the inside of an oil pan 108. Oil accumulated inside the filter 106 returns to the oil pan 108 through the return pipe 110.

A check valve 112 is provided near the bottom end of the return pipe 110. The check, valve 112 may be installed above an oil top limit line 114 of the oil pan 108, such that it is not submerged in oil.

The oil in the filter 106 returns to the oil pan 108 by gravity, through a height difference Δh.

Referring to FIG. 2, the cheek valve 112 includes a projection 205 and a covering 206.

An oil passage hole 202 is provided at the end of the return pipe 110. The projection 205 of the check valve 112 is inserted through the hole 202, and the covering 206 of the cheek valve 112 covers the end side surface of the return pipe 110. The oil flows downward through the return pipe 110, through the gap between the hole 202 and the projection 205, and out the sides at the bottom of the check valve 112 to return to the oil pan 108.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 

1. A crank-case ventilation filter set, comprising: a crankcase ventilation filter for filtering oil from blow-by gas; an inlet pipe configured to transport the blow-by gas from an engine to the filter; an outlet pipe configured to transport the blow-by gas from the filter to an intake device; an oil pan provided at a lower portion of the engine; an oil return pipe configured to transport oil from the filter to the oil pan; and a valve for preventing back-flow of oil, provided on the end of the oil return pipe, and disposed in the oil pan above an oil top limit line of the oil pan, wherein the valve includes: an end wall closing the end of the oil return pipe, the end wall having a hole a covering that covers the hole of the oil return pipe; and a projection extending from the covering and through the hole of the oil return pipe, wherein an end portion of the projection is wider than the hole.
 2. The crank-case ventilation filter set of claim 1, wherein the oil return pipe is configured to transport the oil by gravity. 